At present, the 3rd Generation (3G) mobile communication technology is widely used, and a 4th Generation (4G) mobile communication technology will emerge in the future. However, both the 3G mobile network and the future 4G mobile network will encounter some problems, for example, poor terminal access quality at the edge of cellular cell coverage, existing of coverage hole and coverage blind area, and poor indoor coverage. To solve these problems, main technical solutions proposed at present include relay technology, repeater technology, and backhaul technology.
The backhaul technology may employ a wireless backhaul transmission manner. The wireless backhaul transmission manner uses a wireless-mode mobile terminal and a Base Station (BS) as transmission bearers in the same or different wireless mode, that is, the wireless backhaul transmission manner uses two stages of the same wireless access link or different wireless access links at the same wireless mode or different wireless modes are cascaded. In the wireless backhaul transmission manner, in terms of Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), or Worldwide Interoperability for Microwave Access (WiMAX) system, a target is to realize backhaul transmission while the impact on the existing protocols are lowered as much as possible.
FIG. 1 is a schematic diagram of performing data forwarding by using a wireless backhaul transmission manner in the prior art.
In a solution as shown in FIG. 1, it is assumed that core network elements of a Primary BS (PBS) and a Secondary BS (SBS) are logically separated, that is, all data streams from the SBS transparently pass through the PBS and the core network element of the PBS, and are then transmitted to the core network element belonging to the SBS. The PBS is, for example, an eNB, and the SBS is, for example, a Pico or a Femto.
As shown in FIG. 1, a common terminal, an SBS, a backhaul terminal, a PBS, core network elements of the PBS (including a control plane node (for example, a Mobility Management Entity (MME)) and a user plane node (for example, a Serving-Gateway (S-GW) and a PDN-Gateway (P-GW)), and core network elements of the SBS (including a control plane node and a user plane node) are included. In FIG. 1, a dashed line represents a control plane signaling flow, and a solid line represents a user plane data stream.
The backhaul terminal is a special common terminal, and mainly serves for transmission and relay in a network.
When the data (for example, the user plane data stream or the control plane signaling flow) sent from the SBS is transmitted to the PBS through the backhaul terminal, the PBS performs tunnel encapsulation on the data, and transmits the data to the core network element of the PBS, and then the data is transparently transmitted to the core network element of the SBS. The user plane data stream passes through the core network elements being the S-GW and the P-GW of the PBS, and is then transmitted to the core network elements being the S-GW and the P-GW of the SBS. The control plane signaling flow passes through the core network elements being the S-GW and the P-GW of the PBS, and is then transmitted to the core network element being the MME of the SBS. In addition, as for data sent from the core network element to the backhaul terminal, the PBS needs to perform tunnel decapsulation on the data, and then sends the data to the backhaul terminal.
During the researching and practicing of the prior art, the inventors find that the prior art has the following problems.
In the prior art, when data sent from the SBS passes through the PBS, the data needs to be performed one-time tunnel encapsulation. As a result, waste of transmission bandwidth is caused by tunnel encapsulation.